1. Field of the Invention
A hand-manipulatable light-weight steamer in which steam is generated by electrolyte heating and applied to wallpaper to loosen the adhesive bond between the wallpaper and the substrate.
2. Description of the Prior Art
Wallpaper is, to a very substantial extent, held to an underlying substrate by the interposition of a layer of adhesive which is applied as a paste and subsequently dries to perfect an adhesive bond. With the passage of time, it becomes desirable to remove such wallpaper, either because it has faded or has been abused or because it is desired to change the decor of a room. Most wallpaper is pervious to steam and most adhesives employed are water-soluble. Accordingly, with such wallpapers and such adhesives it has been the practice to weaken or destroy the adhesive bond by causing steam to penetrate the wallpaper and condense in back of the wallpaper between the wallpaper and the substrate so as to form water which wets the dried adhesive and greatly reduces its holding capacity to the extent that the wallpaper then can be peeled or scraped from the substrate without materially affecting the integrity of the substrate. The heat of the steam aids in loosening the bond. The foregoing enables fresh wallpaper or paint to be applied to the substrate without any substantial degree of preparation. It is noted, in passing, that there are wallpapers that are impervious to steam. Frequently, these can be stripped off to expose an underlying paper support which then can be steamed off.
Usually, the steaming of previously applied wallpaper is effected by a professional paperhanger. However, for some time, due to the desire of homemakers to turn their hands to advantage and, furthermore, due to the steadily increasing price of skilled labor, and to the increasing amount of leisure time with the shortening of working hours, home owners and apartment dwellers have increasingly turned to the stripping of applied wallpaper, sometimes with the subsequent application of new wallpaper and sometimes just to save money in connection with the removal of old wallpaper with the intent that a professional paperhanger will be permitted to hang fresh wallpaper.
When a professional paperhanger was requested to remove wallpaper, he frequently employed special equipment for this purpose, disdaining the slower process of simply applying water to the existing wallpaper and waiting for it to soak through to the underlying adhesive, because this was a time-consuming and untidy procedure. Equipment most commonly used for the aforesaid purpose was a somewhat heavy vessel designed to rest on the floor and having a heater associated with it. The vessel contained water, the heater brought the water to a boil, the steam generated in the vessel was led by a flexible supply circuit to a hand-held plenum chamber from which condensed water was led back to the vessel by a flexible return conduit. A conduit was not always employed. The plenum chamber included a handle to enable an operator to move the chamber over applied wallpaper on a wall of a room. The heater employed sometimes used gas and sometimes used liquid fuel. More modern steamers employed electric heaters of the resistance type. This type of wallpaper steamer was uniquely adapted for utilizaiton by a professional paperhanger because it contained a considerable amount of water and did not require frequent refilling. However, it did not find favor with home owners and apartment dwellers because it was too bulky and heavy and far too costly for the occasional use to which it was put by such persons. Moreover, this type of wallpaper steamer transmitted live steam from the steam generating vessel to the plenum chamber and, should a break develop in the conduit employed for transmission of the steam, a potentially dangerous situation could be created.
It has been proposed to improve the aforesaid professional wallpaper steamers by eliminating the large heating vessel and supplanting the same with a water supply conduit from a locally available tap which conduit ran to a heating chamber adjacent the plenum chamber. This, too, although useful for day-to-day operation, was cumbersome to employ due to the presence of the flexible water conduit. It also was costly and bulky and, hence, was not a pactical device for occasional use.
It also has been proposed to construct a wallpaper-removing steam-applying device having its own water chamber and plenum chamber and having an electric resistance heater associated with the water chamber. Such devices have been suggested only where the heating device utilized an electric resistance heater which necessarily was external to the water heating chamber. These devices had serious drawbacks which have prevented the successful manufacture of a portable hand-manipulatable steamer for loosening the bond between wallpaper and a substrate. The principal defects arose from the use of a heater of the type mentioned. It was comparatively bulky, thereby increasing the size of the steamer. It was susceptible to breakdown because electric resistance heaters are notoriously subject to the drawback that the heating coils become fragile and are prone to break. Because the coil was external to the heating chamber, the heat was not employed efficiently and, moreover, the heat was conducted in various directions so that the entire steamer could become too hot or too uncomfortably warm to hold. Additionally, if the resistance heater were located inside the water chamber, the structure became expensive to make and the heating element became difficult to remove in the case of breakage.
Furthermore, hand-manipulatable portable steamers of the type mentioned continued to operate so long as the electric switch to the heating element was closed, so that it was possible to burn out the element or to overheat and destroy the steamer. In addition, if a steamer of the type just described were placed down on a horizontal surface and the operator forgot to turn off the switch to the heating element, the heating element easily could burn out because the conduction of heat between the heating element and the water in the chamber might be less effective due to a shift in the location of the water in such chamber. Hence, such steamers were susceptible to destruction and to damage of surrounding objects or to the operator.